The invention relates to an electrical plug and socket connector having an elongated metal connector frame (shell) which can be affixed to an apparatus housing or the like.
The connector frame consists of a frame front part and a frame rear part. The plug and socket connector further includes a two-piece insulating body fabricated of insulating materials and enclosed between the two frame parts, the insulating body having a plurality of bores to accommodate therein a plurality of contact elements in the form of plug pins, plug sockets, or the like which elements become enclosed in and insulated by the insulating materials of t he insulating body. These contact elements are connectable to electrical conductors on the rear side of the connector, and at the front side of the connector they can be engaged with mating contact elements which are assembled into a corresponding multiconductor (i.e., "multipole") socket or plug member and which are connected to a connecting cable.
Further, the insulating body includes a front supporting and guiding plate fabricated of thermoplastic plastic which plate has bores to accommodate the front ends (i.e.. frontward regions) of the contact elements.
The insulating body also includes a rear plate with corresponding bores for the rear ends (i.e., rearward regions) of the contact elements.
Plug and socket connectors of this type have been widely adopted in practice. They are referred to as "D-sub" type connectors. Standards for their dimensions and pole configurations are presented in, e.g., DIN 41652, MS 18274, and MS 18276. This type of plug is in Protective Class IP 54 or better, according to DIN 40050. In known D-sub connectors with two-piece insulating bodies, not only the front plate but also the rear plate of the insulating body is fabricated of thermoplastic plastic and is configured such that contact elements can be mechanically mounted therein for crimp connection of conductors to the contact elements.
It has been found that for all plug and socket connections of this type, sealing against dust and water cannot be achieved without additional measures, e.g. adhesive bonding of the contact elements and appropriate sealing of the pieces of the insulating body into the metal connector frame with the aid of elastic sealing compounds. These measures are inconvenient, time-consuming, and costly. Further, when such measures are employed in serial production they do not ensure reproducible seal conditions (i.e., seal quality), thereby necessitating costly testing and other quality assurance procedures. They have the further disadvantage that when adhesive bonding is employed it results in rigid fixing of the positions of the contact elements in the insulating body, whereby the only options for connecting cables to the connector members are in situ soldering techniques. Moreover, additional measures are required in cabling (i.e., manufacturing of connector cables), on account of the need to adjust to slight dimensional variations; and these raise manufacturing costs.
An underlying object of the present invention is to improve the electrical plug and socket connector of the type described above, such that it is sealed against water and dust, by relatively simple fabricating techniques, and so that the front ends of the contact elements are still movable to a small degree so as to adjust to slight dimensional differences, and further, so that, even after the cable has been attached to the contact elements, the contact elements can be pushed into the bores of the insulating body and affixed therein Without degrading the seal.
This problem is solved by the present inventive plug and socket connector which is distinguished essentially in that the rear plate of the insulating body is in the form of a sealing plate of rubberlike elastic material, and this sealing plate is particularly dimensioned with respect to the supporting and guiding plate, which supporting and guiding plate rests against the outwardly curved (or flared) flange of the front part of the frame. Namely, the sealing plate is so dimensioned with respect to the face of the supporting and guiding plate which is directed toward it, that after the two frame parts are fastened together the edge region of the sealing plate which faces away from the supporting and guiding plate is held in compression against a supporting edge region of the rear frame part, so as to furnish a trouble-free seal. And furthermore, the bores passing through the sealing plate are configured to have ring-shaped grooves with supporting shoulders for engaging ring-shaped collars on the contact elements which collars project radially outwardly and are provided to fix the position of the contact elements when the contact elements are pushed into the connector assembly.
It has been found that a plug and socket connector according to the present invention ensures a trouble-free seal without the need to apply adhesives or sealing compounds during or after the mounting of the contact elements.
With the aim of providing a trouble-free seal while still allowing a certain movement of the contact elements after the contact elements have been mounted in the insulating body, it has proven advantageous if there are provided narrowed regions of smaller diameter in the bores in the sealing plate in the region of the openings of these bores into the corresponding bores in the front supporting and guiding plate. When the contact elements are pushed into the bores into which they are to be respectively installed, the rubberlike elastic material of the rear sealing plate is forced radially outward, as a result of which the contact elements are gripped and surrounded in a manner which provides a tight seal for a long service life. Nonetheless, even after the contact elements are installed they may be rotated to a certain extent around their longitudinal axis if required. It has proven advantageous for enhancing the seal if, according to a further refinement of the invention, in the sealing plate at a distance from each bore containing a contact element, a ring-shaped slot is provided which extends concentrically to the corresponding bore, with a matching ring-shaped axial projection on the supporting and guiding plate extending into and engaging the ring-shaped slot.